Method of making a bearing for structural elements

ABSTRACT

A bearing for structural elements is made by first providing at least two foil components each of which has a free surface which in use of the bearing is to slidingly engage the free surface of the respective other component. Thereupon the free surfaces are placed into face-to-face abutment and the two components are subjected to such forces and movements as at least approximate those which the finished bearing is expected to encounter in actual use, for instance by advancing the foil components between two pressure rollers rotating in mutually opposite directions. In so doing the bearing has imparted thereto a predetermined at least substantially constant coefficient of friction before it is subjected to actual use, and which coefficient of friction it could otherwise only attain over a period of time in actual use. actual use.

[is] 3,654,684 [451 Apr. 11,1972

[54] METHOD OF MAKING A BEARING FOR STRUCTURAL ELEMENTS [72] Inventor:l-lans Alfred Nell, Klippe l7, Langenberg,

Germany [22] Filed: Mar. 3, 1970 [21] Appl.No.: 16,005

[30] Foreign Application Priority Data Mar. 3, 1969 Germany ..P 19 10727.8

[52] US. Cl ..29/l49.5 NM, 29/155 R, 29/404, 29/434 [51] Int. Cl. v.B23pl1/00, B2ld 53/10, B23q 17/00 [58] Field of Search ..29/l49.5, 149.5 NM,404, 148.4 A, 29/l48.4, 434, 155 R 3,195,221 7/1965 Martin et al..29/149.5 NM 3,251,117 5/1966 Maynard et a1 ..29/404 X 3,387,985 6/1968Huber ..29/l48.4 X

Primary Examiner--Thomas l-l. Eager Attorney-Michael S. Striker [5 7]ABSTRACT A bearing for structural elements is made by first providing atleast two foil components each of which has a free surface which in useof the bearing is to slidingly engage the free surface of the respectiveother component. Thereupon the free surfaces are placed intoface-to-face abutment and the two components are subjected to suchforces and movements as at least approximate those which the finishedbearing is expected to encounter in actual use, for instance byadvancing the foil components between two pressure rollers rotating inmutually opposite directions. In so doing the bearing has impartedthereto a predetermined at least substantially constant coefficient offriction before it is subjected to actual use, and which coefi'lcient offriction it could otherwise only attain over a period of time in actualuse. actual use.

8 Claims, 5 Drawing Figures METHOD OF MAKING A BEARING FOR STRUCTURALELEMENTS BACKGROUND OF THE INVENTION The present invention relatesgenerally to bearings for structural elements, and more particularly toa method of making such bearings. Still more specifically the inventionrelates to a method of making bearings for structural elements whichbearings have a substantially constant coefficient of friction.

It is known that structural elements, such as supports, walls or thelike in buildings and other structures are frequently provided withbearings, or more particularly with slide bearings which are interposedbetween the respective structural element and a support, for instance asill on which a wall is erected. These known slide bearings with whichthose skilled in the art are conversant, have a coefficient of frictionwhich, as the first load changes and concomitant relative movement ofthe structural elements between which the bearing is interposed takeplace, is frequently so high that undesired problems occur, such asdamage in form of cracks or the like in structural elements with whichthe bearing cooperates. In other words, there is the danger that thestructural elements are damaged as a result of relative movements beforethe sliding bearing interposed between and contacting such structuralelements achieves after a certain period of time the necessary lowcoefficient of friction which guarantees that the structural elementscan perfonn the permissible relative movements without such damage.

SUMMARY OF THE INVENTION It is, accordingly, an object of the presentinvention to overcome these disadvantages.

More particularly, it is an object of the present invention to provide amethod of making a bearing for structural elements which is notpossessed of these disadvantages.

Still more specifically it is an object of the present invention toprovide a method of making such a bearing for structural elements whichhas prior to its actual use a coefficient of friction which issubstantially constant or, expressed differently, which has already acoefficient of friction at least approximating that which it couldotherwise attain only over a period of time in actual use.

In pursuance of the above objects, and others which will become apparenthereafter, one feature of the invention resides in a method of making abearing for structural elements which, briefly stated, comprises thefirst step of making a bearing having at least two components eachofwhich is provided with a free surface which in use of the bearing isto slidingly engage the free surface of the respective other component.The second step involves placing the free surfaces into face-to-faceabutment with one another. Thereupon, the components are subjected tosuch forces and movements as at least approximate those which thefinished bearing is expected to encounter in actual use. In this mannerthere is imparted to the bearing an at least substantially constantcoefficient of friction approximating the coefficient of friction whichit would normally attain after undergoing actual use for a certainperiod of time. A bearing constructed in this manner and interposedbetween two structural elements which are to be permitted to performcertain relative movements will not cause the aforementioneddifficulties.

According to the invention it is also possible to pass a foil offriction-promoting synthetic plastic material between and in pressurecontact with at least cooperating pressure rollers one of which isdriven in the direction of movement of the coil whereas the other memberis driven in the direction opposite the movement of the foil. In thismanner that surface which comes in contact with the roller driven in thedirection opposite the movement of the foil can for instance be preparedin accordance with certain desired operating conditions. This has theadvantage that bearings of the type under discussion can be produced inseries of desired size, rather than individually.

According to a further concept of the invention it isadvantageous-particularly with respect to bearings of the type underdiscussion which are to be subjected to particularly critical loadconditions-that the abutting free surfaces be subjected to sliding orrotating displacement with reference to one another while they arepressed against each other. In this manner the two surfaces can besubjected to such forces and movements that the bearing will have an atleast substantially constant coefficient of friction when it is finishedand before it is subjected to actual use.

It may be advantageous if the material of at least one of the componentshas, at least in the region of its free surface, a degree of hardnesswhich is lesser than that of the other component. One of the surfacesmay advantageously consist of synthetic plastic material.

It is also possible to coat the free surfaces during the step ofsubjecting the components to such forces and movements as approximatethose which the finished bearing is expected to encounter in actual use,with a friction-promoting-that is a low coefficient offriction-material, such as tetrafluorethylene, graphite, silicone or ananalogous material.

In addition it is possible to so subject the two components to pressurethat the material of one of the components at the interface of the twosurfaces will flow under the influence of this pressure, whereby anyunevennesses in the two surfaces will be smoothed by an evendistribution of the flowing material over the two surfaces, so that theyare smooth and a still lower coefficient of friction is attained thanwould otherwise be possible.

The novel features which are considered as characteristic for theinvention are set forth in particular in the appended claims. Theinvention, itself, however, both as to its construction and its methodof operation, together with additional objects and advantages thereof,will be best understood from the following description of specificembodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a diagrammatic fragmentaryelevation illustrating structural elements of the type with which thebearing according to the present invention is to be used;

FIG. 2 is a view similar to FIG. 1 illustrating the structural elementswith a bearing made according to the present invention interposedbetween them;

FIG. 3 is a fragmentary diagrammatic exploded detail view illustratingthe bearing of FIG. 2;

FIG. 4 illustrates a further embodiment in a view analogous to FIG. 3;and

FIG. 5 is a diagrammatic detail view illustrating still a furtherembodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Discussing now the drawing indetail, and firstly FIG. 1 thereof, it will be seen that referencenumeral 1 identifies a first structural element, for instance a sill,which is supported on and in suitable manner connected with a support 2,for instance a foundation of a structure. A second structural element 3is disposed on and rests upon the first structural element 1. Theelement 3 may be a wall, and both have been illustrated as masonry, butcould also be of different composition. Reference numeral 6 identifiesthe interface between the structural elements 1 and 3, that is the faceat which the two abut one another. The arrow 4 identifies the verticalload acting upon the elements 3 and 1, for instance the weight of theelement 3 which rests upon and acts upon the element 1. Referencenumeral 5 identifies the double-headed arrow which designates by way ofexample directions of relative movement of the elements 1 and 3, and inFIG. 1 of course it will be appreciated that such movement wouldordinarily be performed only by the element 3 with reference to theelement 1.

FIG. 2 illustrates how conventionally a slide bearing is interposedbetween the two structural elements 1 and 3. This slide bearing is ofthe type constructed in accordance with the present invention. Likereference numerals identify like elements. The slide bearing isidentified with reference numeral 7 in FIG. 2 and will be seen to becomposed of two components 8 and 9 which are interposed between thestructural elements 1 and 3. It should be pointed out, parenthetically,that of course in place of the two elements 1 and 3 there could be asingle element-a composite of the elements 1 and 3-and the bearing 7could be interposed between this single element and the support 2.

FIG. 3 shows details of the bearing 7 of FIG. 2. Specifically, each ofthe components 8 and 9-whose configuration is immaterial for anunderstanding of the invention-has an exposed free surface 8a and 9a,respectively, and while the components 8 and 9 have been illustratedasbeing spaced apart in FIG. 3 for better understanding, it will beappreciated that when the bearing 7 is in actual use as shown in FIG. 2,the surfaces 8a and 90 will be in face-to-face abutment with each other.In other words, the faces 8a and 9a will slide one upon the other ifrelative movement occurs between the elements 1 and 3.

The bearing 7 is produced in accordance with the present invention bymaking the elements 8 and 9, placing their surfaces into face-to-faceabutment and then subjecting the components 8 and 9 to forces andmovements which at least approximate those which the bearing 7 willencounter when in actual use as illustrated in FIG. 2. In other words,forces such as indicated by the arrow 4 and by the arrow 5 are appliedto the bearing composed of the components 8 and 9, and the finishedbearing will then have a coefficient of friction which is at leastsubstantially constant and which at least approximates that which itcould attain in actual use-and not produced in accordance with thepresent inventiononly over a period of time if interposed between theelements 1 and FIG. 4 shows an embodiment of the invention where againthe components 8 and 9 are provided to constitute the bearing 7. Here,however, at least one of the surfaces-in the illustrated embodiment thesurface 8a of the component 8-a friction-reducing material, that ismaterial which has a low coefficient of friction. This coating isidentified with reference numeral 10 and may be of a suitable material,such as tetrafluoroethylene (commercially known under the trade nameTeflon), graphite, silicone or the like. The coating 10 may be in formof a foil but it may also be appliedfor instance in form of a spray orthe like-during the actual preparation of the bearing, that is while thecomponents 8 and 9 are subjected to such forces and movements which atleast approximate the forces and movements which the finished bearing isexpected to encounter in actual use.

FIG. 5,- finally, shows a manner in which a foil 10a of syntheticplastic material having a low coefiicient of friction can be prepared.This foil 10a may for instance correspond to the coating 10, although asmentioned with respect to FIG. 4 the coating 10 may also be applied as aspray or the like. If the foil 10a is involved, however, then it may beadvanced in the direction of the arrow 13 between and in pressurecontact with the two cooperating pressure rollers 11 and 12. Of these,one (namely the roller 12) rotates in the direction of advancement ofthe foil 10a as indicated by the arrow 12a. The other roller 11,however, rotates in the direction oppositely the advancement of the foil10a, as identified with the arrow 11a. The result is that the surface ofthe foil 10a which is contacted by the roller ll-that is the rollerwhich rotates in the direction oppositely the direction of advancement13 of the foil l0acan be prepared in suitable manner, for instance indescribed above.

ile the invention has been illustrated and described as embodied in amethod of making a bearing for structural elements, it is not intendedto be limited to the details shown, since various modifications andstructural changes may be made without departing in any way from thespirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can by applying current knowledgereadily adapt it for various applications without omitting featuresthat, from the standpoint of prior art, fairly constitute essentialcharacteristics of the generic or specific aspects of this inventionand, therefore, such adaptations should and are intended to becomprehended within the meaning and range of equivalence of thefollowing claims.

What is claimed as new and desired to be protected by Letters Patent is:

l. A method of making a bearing for structural elements of buildings,bridges and the like, comprising the first step of making a bearinghaving at least two components each having a free surface which in useof the bearing is to slidingly engage the free surface of the respectiveother component, at least one of said components being constituted atleast at the surface thereof by a foil of synthetic plastic material,and said components together having a first coefficient of friction; thesecond step of placing said free surfaces into face-to-face abutmentwith one another and accommodating said components between relativelydisplaceable pressure-exerting instrumentalities; and the third step ofsubjecting said components by engagement with said instrumentalities topressures and relative movements which at least approximate those thefinished bearing is expected to encounter in actual use, whereby toimpart to said bearing an at least substantially constant second lowercoefficient of friction prior to its actual use.

2. A method as defined in claim 1, wherein said third step comprisessliding the components with reference to one another.

3. A method as defined in claim 1, wherein said third step comprisesturning said components with reference to one another.

4. A method as defined in claim 1, wherein at least one of saidcomponents has at least in the region of said free surface thereof adegree of hardness which is smaller than that of the other component.

5. A method as defined in claim 1; and further comprising the step ofcoating at least one of said free surfaces with a substance having a lowcoefficient of friction.

6. A method as defined in claim 5, wherein the step of coating iscarried out during displacement of said components with reference to oneanother.

7. A method as defined in claim 1, wherein said third step comprisesexerting upon said components a pressure requisite for causing thematerial of at least one of said components to flow at the interfacebetween said free surfaces.

8. A method as defined in claim 1; and further comprising the step ofpreparing said foil by advancing the same in a predetermined directionbetween and in pressure-contact with a pair of cooperating pressurerollers one of which rotates in said predetermined direction and theother of which rotates oppositely to said predetermined direction.

1. A method of making a bearing for structural elements of buildings,bridges and the like, comprising the first step of making a bearinghaving at least two components each having a free surface which in useof the bearing is to slidingly engage the free surface of the respectiveother component, at least one of said components being constituted atleast at the surface thereof by a foil of synthetic plastic material,and said components together having a first coefficient of friction; thesecond step of placing said free surfaces into face-to-face abutmentwith one another and accommodating said components between relativelydisplaceable pressure-exerting instrumentalities; and the third step ofsubjecting said components by engagement with said instrumentalities topressures and relative movements which at least approximate those thefinished bearing is expected to encounter in actual use, whereby toimpart to said bearing an at least substantially constant second lowercoefficient of friction prior to its actual use.
 2. A method as definedin claim 1, wherein said third step comprises sliding the componentswith reference to one another.
 3. A method as defined in claim 1,wherein said third step comprises turning said components with referenceto one another.
 4. A method as defined in claim 1, wherein at least oneof said components has at least in the region of said free suRfacethereof a degree of hardness which is smaller than that of the othercomponent.
 5. A method as defined in claim 1; and further comprising thestep of coating at least one of said free surfaces with a substancehaving a low coefficient of friction.
 6. A method as defined in claim 5,wherein the step of coating is carried out during displacement of saidcomponents with reference to one another.
 7. A method as defined inclaim 1, wherein said third step comprises exerting upon said componentsa pressure requisite for causing the material of at least one of saidcomponents to flow at the interface between said free surfaces.
 8. Amethod as defined in claim 1; and further comprising the step ofpreparing said foil by advancing the same in a predetermined directionbetween and in pressure-contact with a pair of cooperating pressurerollers one of which rotates in said predetermined direction and theother of which rotates oppositely to said predetermined direction.